Diet makes a difference in fighting against hospital-acquired infection: Study

In contrast with the popular opinion that low carb and high protein diets help in maintaining the waistline, a new study suggests that the same may lead to alleviation of hospital-acquired infections.

The study surrounding the hospital-acquired infection Clostridioides difficile was published in the journal mSystems.

In the study, scientists found that an interaction between antibiotic use and a high-fat/high-protein diet exacerbate C. diff infections in mice. Conversely, they found that a high-carbohydrate diet - which was correspondingly low in fat and protein - nearly eliminated symptoms.

C. diff, an intestinal infection designated as an urgent threat by the U.S. Centers for Disease Control and Prevention, is often acquired when antibiotics have wiped out the "good" bacteria in the gut. Hundreds of thousands of people are diagnosed with C. diff infections each year and more than 10,000 die.

"Every day, we are learning more about the human microbiome and its importance in human health. The gut microbiome is strongly affected by diet, but the C. diff research community hasn't come to a consensus yet on the effects of diet on its risk or severity," said the lead microbiologist Brian Hedlund.

"Our study helps address this by testing several diets with very different macronutrient content. That is, the balance of dietary carbohydrate, protein, and fat were very different," added Hedlund.

Though studies suggest dietary protein exacerbates C. diff, there's little or no existing research exploring the interaction of a high-fat/high-protein diet with the infection.

Hedlund and the co-author of the study, Ernesto Abel-Santos, a UNLV biochemist, caution that the study was conducted using an animal model, and more work is underway to begin to establish a link between these diets and infections in people.

"Extreme diets are becoming very popular but we do not know the long-term effects on human health and specifically on the health of the human gut flora. We have to look at humans to see if it correlates," said Abel-Santos.

Recent studies suggest that because antibiotics kill bacterial species indiscriminately, the medications decimate populations of organisms that compete for amino acids, leaving C. diff free to propagate.

"It's clear that it's not just a numbers game," said Hedlund.

The new work suggests that diet may promote microbial groups that can be protective, even after antibiotics. For an infection to flourish, Hedlund said, "you might need this combination of wiping out C. diff competitors with antibiotics and then a diet that promotes overgrowth and disease."

"Lots of papers say that a lower microbial diversity is always a bad thing, but in this case, it had the best disease outcome," said Abel-Santos.

However, he cautions that a high-carb diet could lead to animals becoming asymptomatic carriers that can disseminate the infection to susceptible subjects.